There is an effort underway to port linux to the Topfield TF5800 PVR, it uses the NEC UPD61130 EMMA2 chipset. This PVR includes support for running external programs under its proprietary OS. For the initial experiments a small linux loader program has been written similar to the old Windows "loadlin" program. The kernel and ramdisk is loaded into memory, all running operations halted (as far as possible), interrupts disabled and finally the kernel and ramdisk copied to appropriate addresses and executed. This works part of the time but it is prone to crashing when the kernel is booted. It is suspected that some interrupt or DMA process is still running which corrupts memory and it isn't clear how to shut it down. It seems that documents for this chipset are only available under NDA from NEC: is that correct? Does anyone have any details how to "disable everything" or any pointers to public code which might do that?
